I flagged a question without understanding it's correct meaning.
Is it possible to delete/remove if once I flagged incorrectly for a question ?
Following information from help center is helpful:
Is there any way to remove flags?
There is often no need, as offensive and spam flags expire after 48 hours if the thresholds aren't reached.
Rolling back a post to a previous state will revert to the number of offensive flags from that particular revision. This allows the OP (or someone else with edit rights) to rollback a post that someone else made offensive in a later revision. However as a general user, once you mark a post as offensive, you cannot take it back.